The output voltage and frequency of PM alternators is essentially determined by the rotor speed, which present challenges where the rotor speed cannot be independently controlled. Also, controllability in low- or no-load conditions requires using regulation apparatus, such as a shunt regulation system, to draw current from the machine if the voltage increases above a given maximum allowable value. But these systems add weight and complexity. It would therefore be desirable to improve the controllability of electric alternators under a low or no-load condition.